Skip to main content


Volume 464: debated on Wednesday 10 October 2007

To ask the Secretary of State for the Home Department what rules apply to mobile police units on (a) carrying breathalyser kits and (b) the procedure to be followed in deciding to take citizens to the police station for breathalysing when kits are not carried; and if she will make a statement. (156639)

Breath test devices currently available for use outside police stations are screening devices, used for a preliminary test to obtain an indication whether a person’s alcohol level is likely to be above the prescribed limit. If a person tests positive, he can be arrested, taken to a police station and required to take an evidential test.

There is no statutory requirement on mobile police units to carry breath screening devices. Vehicles engaged in traffic law enforcement or responding to traffic incidents are however very likely to, and other vehicles may do. This is an operational equipment matter for the chief officer. If the vehicle does not have a screening device, one will normally be readily available and the person to be tested can be required to remain a reasonable length of time for it to arrive. Failure to co-operate with a preliminary test when the officer reasonably suspects there is alcohol in the person’s body is an offence for which the person can be arrested.

In addition to the offence of driving while over the prescribed limit, there is a separate offence of driving whilst under the influence of drink. An officer can arrest for this offence and subsequently require an evidential test provided he has reasonable grounds for suspecting the offence and an arrest is necessary for its prompt and effective investigation.

Decisions as to arrest, etc are operational matters for the police on each occasion.